Little is known about the trajectory of the force of mortality (hazard of death) at advanced ages among non-human species. Furthermore, little is known about the trajectory of the force of mortality at advanced ages among any species, human or non-human, when individuals all live under very similar environmental conditions. This proposal is designed to shed light on these two questions by gathering, analyzing, and publishing survival data on one million Mediterranean fruit flies raised in individual containers under carefully controlled conditions. The data will be used to analyze six sets of questions of prime interest to this program project on oldest-old mortality: -- How much heterogeneity is there in individual lifespans under carefully controlled conditions? -- Does the species lifespan (i.e., the maximum age attainable by an individual in the species) appear to be deterministic or probabilistic? -- What is the shape of the trajectory of the force of mortality at older ages? -- Does the force of mortality appear to have two components, a "premature death" and a "senescent death" component? -- How do male and female mortality trajectories compare? -- How do the mortality trajectories for different size pupae compare? These six sets of questions will be addressed in two ways. First, the demographer's standard approach -- the construction of life tables -- will be employed. Second, the survival data, with covariates, will be analyzed using parametric methods of survival analysis.